Gallup Daily: Presidential Race Narrows Slightly

Obama leads by two to seven points among likely voters

PRINCETON, NJ -- The gap between Barack Obama and John McCain in Gallup Poll Daily tracking from Saturday through Monday has narrowed slightly, and Obama is now at 49% of the vote to 47% for McCain among likely voters using Gallup's traditional model, and at 51% to 44% using Gallup's expanded model.

Both candidates continued vigorous campaigning on Monday. One forthcoming event with the potential to affect voter sentiments is a 30-minute Barack Obama paid program, for which his campaign has purchased time on Wednesday night on a number of national broadcast and cable television networks.

The two percentage point margin for Obama over McCain in today's traditional likely voters result, based on Gallup Poll Daily tracking from Oct. 25-27, is not the first time the race has been this close; it matches the two-point Obama margin that held for three straight reporting periods spanning Oct. 13 -17, a week and a half ago. The traditional model assumes that turnout will follow the patterns of past elections, in which both current interest in the election and past voting behavior are predictors of actual voting.

Obama's seven-point lead among expanded likely voters, based on a model which makes no assumptions about turnout based on past voting history, is fairly typical of what has been measured over the last two weeks, although slightly narrowed from the last two days' reports. Obama's lowest margin among this expanded group was four points, measured on Oct. 15-17.

Obama is also now at a seven-point margin over McCain among registered voters, 50% to 43%. (To view the complete registered voter trend since March 7, 2008, click here.) -- Frank Newport

(Click here to see how the race currently breaks down by demographic subgroup.)

Survey Methods

For the Gallup Poll Daily tracking survey, Gallup is interviewing no fewer than 1,000 U.S. adults nationwide each day during 2008.

The general-election results are based on combined data from Oct. 25-27, 2008. For results based on this sample of 2,781 registered voters, the maximum margin of sampling error is ±2 percentage points.

Results based on "traditional" likely voters (based on the model taking into account current voting intention and past voting behavior) include interviews with 2,439 voters, and assume a turnout of 60% of national adults. The likely voter sample is weighted to match this turnout assumption, so the weighted sample size is 1,813. The associated maximum margin of sampling error is ±3 percentage points.

For results based on the sample of 2,396 "expanded" likely voters (based on the model taking into account current voting intention only), the maximum margin of sampling error is ±2 percentage points. The expanded likely voter model does not make any assumptions about turnout level.

Interviews are conducted with respondents on landline telephones (for respondents with a landline telephone) and cellular phones (for respondents who are cell phone only).

In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.

Gallup scores each respondent on a scale (usually ranging from 0 to 7 given 7 likely voter questions) for their likelihood to vote. The respondents with the highest scores (usually anyone with a score of 7 and often those who score a 6) are considered likely voters.